The laboratory handles about 40,000 urine samples annually from opiate addicts in a government methadone maintenance program and 55,000 drug exhibits, 40,000 of which warrant opiate analysis. The urinalysis is performed with an automated thin layer chromatography (TLC) procedure rather than a radioimmunoassay technique because of low cost, discrimination, and sensitivity. With 2 technicians, the TLC system can handle 200 samples a day, with each 40-sample batch completed in 90 minutes. The system can detect the presence of codeine or methadone during the same morphine detection test. The heroin analysis procedure, in operation since 1987, requires 4 working days, and 50 heroin possession cases can be processed per day. The methodology consists of a laboratory worksheet description, a presumptive color test, and TLC screenings performed on a production line basis. Opiate quantification is conducted automatically by gas chromatography. The results are all printed by a computer including opiate weights to provide a total weight for reference by the court while making sentencing decisions.